The present invention relates to the material for producing disposable medical appliances, especially relates to the light-degradable material for producing disposable medical appliances.

As the increasing awareness of environment protection, it is limited or forbidden to any production or action which can result in environmental pollution in all over the world. Meanwhile, relevant regulations have been issued. The polypropylene as the light-degradable material is only used for food packing according to the Chinese patent publication No. CN1194275A, which mainly focuses on the international problem of environment pollution i.e. "the white pollution". CN 1 088 227 discloses photodegradable compositions of polyolefins and photosensitizers. However, there is no better solution to deal with the large quantity of usage and discard of disposable medical appliances, such as injectors, dropping bottles, and droppers, those are usually made of polypropylene. While more and more disposable medical appliances are used, the waste medical appliances are left in nature by a large amount. Such medical appliances would decompose in decades, or even longer in nature, because the C-C bonds and C-O bonds in their structure are not sensitive to light. The disposable medical appliances are very useful in preventing from the mutual virus infection. Although it is prescribed in China that all disposable injectors must be sterilized and destroyed on the spot after use, there is no suitable method available to destroy the injectors so that some disposable injectors were used for many times, resulting in severe mutual infection on patients. Therefore it is an important agenda for the governments of each country to prevent the above problem from doing harm to human and pollution to environment. At present, although, the light degradable material is available, it is generally used in food packing. Because the disposable medical appliances require high transparence and high bio-security for the material, the light degradable material for food packing is not suitable for producing disposable medical appliances.

In order to solve above problem that harmfulness brings to people by used disposable medical appliances and pollutant brings to environment, the present invention provides the light-degradable material, obtained from polypropylene resin by adding composite allochromatic agent therein, for producing disposable medical appliances. The allochromatic agent is composed of photoinitiator and sensitizer, wherein the photoinitiator contains ferric citrate (FeC₆H₅O₇) and ferrous pentadione (FeC₅H₈O₂); the sensitizer contains hexachloroacetone (Cl₆C₃O) and acetylbenzene (C₈H₈O). The content of these components is photoinitiator 0.04%~0.08% and sensitizer 0.4%~0.9% based on the weight of polypropylene resin. As in photoinitiator, ferric citrate (FeC₆H₅O₇) is 0.02%~0.04%, ferrous pentadione (FeC₅H₈O₂) is 0.02%~0.04%, and in sensitizer, hexachloroacetone (Cl₆C₃O) is 0.2%~0.45%, acetylbenzene (C₈H₈O) is 0.2%~0.45% based on the weight of the polypropylene resin.

According to the present invention, the disposable medical appliances such as disposable injectors made by light-degradable material remain high transparence, high bio-security, and is insoluble to water. After being used, the medical appliances would change color to yellow while being sterilized by UV rays in short time because of the presence of the composite allochromatic agent.

Reuse of these medical appliances can be thereby avoided. Even when the medical appliances are thrown away in nature, they will keep degrading and decay to powder within 45~75 days while exposing in light. When molecular weight thereof decreases to about 5000, they will decompose to carbon dioxide and water by microorganism in soil as well as the problem of pollution to environment introduced by discarded plastic is resolved. The material is neither toxic nor polluted, and may be as the desired substitute of material for producing disposable medical appliances.

Raise the temperature of high speed stirrer to 90°C, and put 125000g of polypropylene, 25g of ferric citrate (FeC₆H₅O₇), 25g of ferrous pentadione (FeC₅H₈O₂), 250g of hexachloroacetone (Cl₆C₃O) and 250g of acetylbenzene (C₈H₈O) into the high speed stirrer, and stirring for 5 minutes at this constant temperature. Then put the mixture into single-screw extruder using automatic feed equipment, and extrude out the pelletings. The heating temperatures of three parts from feed inlet to outlet of single-screw extruder are 140°C, 200°C,125°C respectively.

Raise the temperature of high speed stirrer to 90 °C , put 125000g of polypropylene, 50g of ferric citrate (FeC₆H₅O₇), 50g of ferrous pentadione (FeC₅H₈O₂), 562.5g of hexachloroacetone (Cl₆C₃O) and 562.5g of acetylbenzene (C₈H₈O) into the high speed stirrer, and stirring for 5 minutes at this constant temperature. Then put the mixture into single-screw extruder using automatic feed equipment, and extrude out the pelletings. The heating temperatures of three parts from feed inlet to outlet of single-screw extruder are 140 °C , 200°C ,125°C respectively.

This is the best mode to carry out the invention. Raise the temperature of high speed stirrer to 90°C, put 125000g of polypropylene, 37.5g of ferric citrate (FeC₆H₅O₇), 37.5g of ferrous pentadione (FeC₅H₈O₂), 406.25g of hexafluoroacetone (Cl₆C₃O) and 406.25g of acetylbenzene (C₈H₈O) into the high speed stirrer, and stirring for 5 minutes at this constant temperature. Then put the mixture into single-screw extruder using automatic feed equipment, and extrude out the pelletings. The heating temperatures of three parts from feed inlet to outlet of single-screw extruder are 140°C , 200°C,125°C respectively.